Tom DeMarco, co-author of "Peopleware" (1987) with timothy-lister, is gerald-weinberg's closest intellectual peer. Both argued that software development is fundamentally a human activity. Where Weinberg approached this from psychology and systems thinking, DeMarco approached it from organizational sociology and empirical measurement (Coding War Games). Their work is complementary: Weinberg on the individual and team psychology, DeMarco/Lister on the organizational environment. DeMarco's "Slack" (2001) also connects to lean software thinking.